Mutation of EZH2 was the first of chromatin-modifying gene alteration to be described in FL and DLBCL.11 In contrast to the inactivating mutations that are spread across the gene in myeloid and T-cell malignancies,32, 33 mutations of EZH2 in B-cell lymphoma are localized to a ‘hotspot'. The gene discussed is EZH2; the disease is diffuse large B-cell lymphoma.